I find Griffiths "introduction to elementary particles" very good, as all of Griffiths books. The level is suitable for a higher level undergraduate I would say.
When I read an introductory course in particle physics I used the book "Particle Physics" by Martin and Shaw. It was quite good and had problems with full solutions in the appendix which is good for selfstudy.
If you just want a reference for particle masses, lifetimes etc. I recommend PDG, the Particle Data Group, their website is pdg.lbl.gov/ .